package com.flink.examples.window;

import com.flink.examples.DataSource;
import org.apache.flink.api.java.functions.KeySelector;
import org.apache.flink.api.java.tuple.Tuple3;
import org.apache.flink.streaming.api.datastream.DataStream;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.streaming.api.functions.source.RichSourceFunction;
import org.apache.flink.streaming.api.windowing.time.Time;

import java.util.List;

/**
 * @Description timeWindow时间窗口（滑动窗口【滑动窗口与滚动窗口的区别，在于滑动窗口会有数据元素重叠可能，而滚动窗口不存在元素重叠】）
 * @Author JL
 * @Date 2020/09/14
 * @Version V1.0
 */
public class TimeWindow {

    /**
     * 遍历集合，返回指定时间滑动窗口下每个性别分区里最大年龄数据记录
     * @param args
     * @throws Exception
     */
    public static void main(String[] args) throws Exception {
        final StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
        //env.setParallelism(1);
        DataStream<Tuple3<String, String, Integer>> inStream = env.addSource(new MyRichSourceFunction());
        DataStream<Tuple3<String, String, Integer>> dataStream = inStream
                .keyBy((KeySelector<Tuple3<String, String, Integer>, String>) k ->k.f1)
                //按时间窗口滑动，每3秒为一个时间窗口，并每次滑动2秒（简单来说：每隔2秒对前3秒内的输入数据流），计算一次
                .timeWindow(Time.seconds(3), Time.seconds(2))
                //注意：计算变量为f2
                .maxBy(2);
        dataStream.print();
        env.execute("flink TimeWindow job");
    }

    /**
     * 模拟数据持续输出
     */
    public static class MyRichSourceFunction extends RichSourceFunction<Tuple3<String, String, Integer>> {
        @Override
        public void run(SourceContext<Tuple3<String, String, Integer>> ctx) throws Exception {
            List<Tuple3<String, String, Integer>> tuple3List = DataSource.getTuple3ToList();
            for (Tuple3 tuple3 : tuple3List){
                ctx.collect(tuple3);
                //1秒钟输出一个
                Thread.sleep(1 * 1000);
            }
        }
        @Override
        public void cancel() {
            try{
                super.close();
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }
}
/*
3> (张三,1,20)
4> (李四,2,24)
3> (王五,1,29)
3> (王五,1,29)
4> (刘六,2,32)
 */